From: Rich Bowen
A common use scenario for mod_substitute is the
+ situation in which a front-end server proxies requests to a back-end
+ server which returns HTML with hard-coded embedded URLs that refer
+ to the back-end server. These URLs don't work for the end-user,
+ since the back-end server is unreachable.
In this case, mod_substutite can be used to rewrite
+ those URLs into something that will work from the front end:
+ ProxyPass /blog/ http://internal.blog.example.com
+ ProxyPassReverse /blog/ http://internal.blog.example.com/
+
+ Substitute "s|http://internal.blog.example.com/|http://www.example.com/blog/|i"
+
ProxyPassReverse
+ modifies any Location (redirect) headers that are sent
+ by the back-end server, and, in this example,
+ Substitute takes care of the rest of the problem by
+ fixing up the HTML response as well.
A common use scenario for mod_substitute is the
+ situation in which a front-end server proxies requests to a back-end
+ server which returns HTML with hard-coded embedded URLs that refer
+ to the back-end server. These URLs don't work for the end-user,
+ since the back-end server is unreachable.
In this case, mod_substutite can be used to rewrite
+ those URLs into something that will work from the front end:
Location (redirect) headers that are sent
+ by the back-end server, and, in this example,
+ Substitute takes care of the rest of the problem by
+ fixing up the HTML response as well.